Railway traffic controlling apparatus



Oct. 6, 1931. L. R. ALLISON ET AL RAILWAY TRAFFIC CONTROLLING APPARATUS Filed Sept. 13. 1950 8 w i a M n F I c QI W 3 w w a Z a T W m a 4 U Y. w i 76 a 5f 6 4 A 0 Z/ M "S a a m.

7 x T m L 6 6% W T W g E y m @a Wm M ii a CF 5 A 0 6 1%. M f m L [A 001 6 LOCO/1107775 um/"tow LEJL/E E. ALL/JON F/PA NA H. NlCl-IOA JO/V 3351 M abto'ww/zz QQJW Patented Oct. 6, 1931 PEATET OFFICE LESLIE R. ALLISON, OF W'ILKINSIBURG, AND FRANK H. NICHOLSON, OF EDGEWOOD BOROUGH, PENNSYLVANIA, ASSIGNORS TO THE UNION SWITCH & SIGNAL COMFAN Y, OF SWISSVALE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA RAILWAY TRAFFEC CONTROLLING APPARATUS Application filed September 13, 1930.

This invention relates to railway traihc controlling apparatus, and particularly to apparatus of the type comprising train carried governing means or cab signals controlled by a master relay which is in turn conthe receivers of the trailing locomotives by the wheels and axles of the leading locomotive. Our invention provides for the repeating in the trailing locomotives of the signals received by the leading locomotive, thus apprising the attendants in the trailing locomotive of trafic conditions in advance. In carrying out our invention, we have provided for operating the master relay of the signalling apparatus of a trailing locomotive in accordance with the operation of the master relay of the signalling apparatus on the leading locomotive. We shall describe certain forms of apparatus embodying our invention and shall then point out the novel features thereof in claims.

In the accompanying drawings: Figure 1 is a diagrammatic view illustrative of our invention.

Figure 2 is a diagrammatic view of a modification.

- ter rela 7. As is well understood in the art,

the primary of the master transformer is connected throughsuitable amplifying apparatus to the usual receiver coils which are positioned at the front of the locomotive and which pick up inductively the current im- Serial IIo. -"=81,616.

pulses supplied to the rails under the control of the customary coding devices responsive to traffic conditions beyond the track section. For the present invention it suflic'es to note that there is induced in the secondary 6 of the transformer 5 alternating current of a frequency equal to the rate at which the current supplied to the rails is interrupted by the coding devices. For example, if the current supplied to the rails is interrupted at the rate of 180 times per minute, alternating current of a frequency of three cycles per second is induced in the secondary 6; if the rail current is interrupted at the rate of 120 times per minute, A. C. of two cycles frequency per second is induced in said secondary; and if the rate of interruption of the rail current is 80 per minute the frequency of the A. C. induced in the secondary 6 is 1 cycles per second. If no current is supplied to the rails, no current is induced in said secondary 6. The master relay 7 which is of the direct current polarized type, is periodically energized in opposite directions by the low frequency alternating current induced in the secondary 6, with the result that the movable contact or armature 8 of said relay alternately engages the fixed contacts 9 and 10 at a frequency equal to that of said alternating current, or, in other words, equal to the frequency of interruption of the current supplied to the rails. The movable contact or armature 8 is connected by wire 11 to oneterminal of a battery B or other suitable source of direct current. Contacts 9 and 10 are connected by wires 12 and 13 respectively, to the ends of the primary winding 14 of a decoding transformer 15. Said winding is also connected, at an intermediate point, through wires 16 and 17 to the opposite terminal of said battery B. Thus, when the armature 8 alternately engages contacts 9 and 10, direct current from said source flows alternately through the upper half and the lower half of the decoding transformer winding 14, causing the magnetic flux of said transformer to alternate in direction at the code frequency and inducing alternating current in the secondary 18 of said transformer. The frequency of said alternating current, is, of

course, equal to the rate of interruption by the coding devices of the current supplied to Associated with the secondary 18, as is well understood, are decoding circuits tuned to the respective coding frequencies, and controlling signals in the locomotive cab so that indications corresponding to said frequencies are given in said cab in response to the current flowing in said secondary. If no current flows in said secondary, as will be the case when no current is supplied to the rails, a signal indicative of that condition is given.

The operations above outlined are well known in the art and further description tnereot is unnecessary to an understanding of the present invention.

The numerals 19, 20 and 21 designate respect ely the master transformer, master relay and decoding transformer of the cab signal equipment in a trailing locomotive coupled to the leading locomotive. T he cab signal equipment of the trailing locomotive is the same as that of the leading locomotive. Thus, in Figure 1, the relay 20 is connected to the secondary or transio-rmer 19 by wires 22, 23, and the movable contact or armature 2i of said relay is alternately engageable with fixed contacts 25, 26. A wire 27 connects contact- Ql with one terminal of a. source 13 of dire current supply. lVires 28, 29, connect contacts 26, respectively, to the ends of the primary winding of decoding transformer 2i; and said winding, at an intermediate point, is connected, through wires 30 and 31, to the opposite terminal of said direct current source.

F or causing;- the signals in the leading loconmti ve to be displayed in the trailing locomotive, we provide means for causing the master relay 20 in the trailing locomotive to operate in accordance ith the operation of master relay 7 of the leading locomotive. As shown in l igure '1, wires 32 and are connected to the wires 12, 13, respectively, which connect the prinary ot transformer 15 to the relay 7, while wires 3t 35, are connected to wires 22, 23 connecting the secondary of the master transformer 19 to the master relay 20 in the trailing locomotiv The wires of the respective pairs 1'? and 31, 32 and 23 i, and 33 and 35, are intercon ected by the usual flexible electric coupl' s S7, between the locomotiies. llesistances, 39, 40 are interposed in the respective wires all, 35, to limit the current therein to the desired alue. The common terminals of windings ell, of the master relay 20 are connected by a wire to wire 31.

\Vhen the contact 8 oi"? the master relay 7 moves into engagement with contact 9, a circuit through the master clay 20 in the trailing locomotive is closed as follows: from one terminal or. source 1) through wire 11, contacts 8 and 9, wires 12 and 32, resistance 39,

wires Sal and 22, winding ll of said relay 20, and wires 31, and 1'? to the other terminal of source B. Current from the same source also flows through winding 42 of relay 20 by way oi wire ll, contacts 8 and 9, wires 12,

32, 3% and 22, the secondar" winding of master transformer 19 and wire 23, returning over wires a3, 31, arid 1?. While the current in coil 12 cl master relay 2O flows in a direction opposite to that in coil all, the relatively high reactance oi the secondary of the master transformer causes the rise and fall of current in coil to lag that in coil 41 by a phase angle approzmhing 90 degrees. The resultant current which produces the flux acting to shilt contact into engagement with 25 is the vector sum oi the currents in coils ll and i2 and is a ways greater than either oi them. The contact 9-1 moves into engagement with contact 25 as soon as this resultant current rises above the pick-up value of the relay.

l'v'hen contact 8 moves into engagement with contact 10, current flows from one terminal. of source B through wire 11, contacts 8 and 10, wires and 3 resistance ll), wires 35 and :23, w iding of relay 20, and thence to the other terminal of source I) through wires 43, 3 and 17. Current also flows from wire 253 through the secondary of transformer 19, wire 22, and winding 1 to wire 4-3. The currents in coils ill and are out of phase with each other, due to the rcactance of the secondar -g of transformer 19 as explained above; and the flux produced by the.

resultant of these two currents is in a direction opposite to that cxistmg when contact 8 was engaged with contact 9. Consflpiently, contact 2% is shit nto en; ment with contact 26.

Thus, as contact 8 of master relay 7 oscillates betwen contacts 9 and 10, contact 24 of master relay 2O oscillates between contacts 25 andQG at the same frequency of oscillation as contact 8. As has been pointed out, the oscillation of contact 8 bet-ween contacts 9 and 10 causes current to flow alternately through the upper half and the lower half of primary winding 14 of decoding transformer 15, and results in the displaying in the cab of the leading locomotive of a signal correspoinling to the frequency oi vibration of said contact. Likewise, the oscillation of contact Q-il liietwe-en contacts and 26 of master relay 20 causes current to flow from source B alternately through the upper and lower halves of the primary of decoding transformer :21, and results in the displaying in the cab of the trailing locomotive of a signal corz'espoacting: to the frequency of oscillation of said contact 24. Since the relay 20 is operated in unison with relay 7, it apparent that the signals displayed in the cab of the leading locomotive manner that said relay 20 is controlled by master relay 7 of the first locomotive.

In Figure 2, the circuit comprising the secondary of the master transformer 5 and the coil of the master relay 7 is normally closed by means of short circuiting plug 45. When two locomotives are coupled together the plug 45 on the trailing locomotive is removed to permit the insertion of a plug or coupling connecting wires 82, 33, respectively of the leading locomotive, with wires 47, 46, in circuit with the secondary of transformer 19 and the coil of relay 20 of the trailing locomotive. The oscillations of relay contact 8 are reproduced by relay contact 24 in the trailing locomotive as follows:

When contact 8 engages contact 9, current flows from one terminal of source B through wire 11, contacts 8 and 9, wire 12, wires 32 and 47, the coil of master relay 20, secondary master transformer 19, wire 46, resistance 48, wire 33, lower half of primary of decoding transformer to wire 16 and the opposite terminal of source B. This current passing through the coil of master relay 20 causes contact 24 to engage contact 25. Then contact 8 moves to engage contact 10, current flows from one terminal of source B through wire 11, contacts 8 and 10, wire 13, wire 33, resistance 48, wire 46, the secondary of transformer 19, the coil of master relay 20, wire 47, wire 32, wire 12, the upper half of the primary of decoding transformer 15, and wire 16 to the opposite terminal of source B. T he direction of fiow of the current through relay 20 is now such as to cause contact 24 to engage contact 26. Thus, as contact 8 oscillates between contacts 9 and 10, contact 24 0scillates with the same frequency between contacts 25 and 26. The resistance 48 limits the flow of current through the coil of master relay 20 to the desired value.

With contact 8 in the'position shown in Figure 2 the passage of the current supplying energyto master relay 20 through the lower half of the primary winding of decoding transformer 15 is in a direction opposite to the flow of decoding current through the upper half of said primary winding, and thus tends to reduce the effective primary current. However, the current returning through the lower half of the primary is small in comparison with the normal primary current in the upper half so that the loss in the decoding current is small. Similarly, when contact 8 engages contact 10, the current returning through the upper half of the primary winding of decoding transformer 15 is small in comparison with the current in the lower half of said winding.

A third method for repeating in the trailing locomotive the cab indication in the leading locomotive is shown in Figure 3, wherein the secondary winding 18 of the decoding transformer 15 is provided with taps to which wires 49, 50 are connected. Vv ire 51 is connected, as shown, to one side of the secondary of master transformer 19, and wire 52 is connected to the other side of said transformer secondary. The wires 49, 50 are connected by the usual plugs or couplings to said wires 51, 52, respectively. It will be seen that the alternating voltage induced in the secondary 18 as the result of oscillation of contact 8 between contacts 9 and 10 will cause an alternating current of the same frequency as that of the oscillation of said contact 8 to fiow through the coil of master relay 20. The contact 24 of said master relay thus is caused to oscillate between contacts 24 and 25 at the same frequency of oscillation as that of contact 8, with the result that the same signal is produced in the cab of the trailing locomotive as in the cab of the leading locomotive.

The terms and expressions which we have employed are used as terms of description and not of limitation, and we have no intention, in the use of such terms and expressions, of excluding any equivalents of the features shown and described or portions thereof, but recognize that various modifications are possible within the scope of the invention claimed.

e claim: q

1. In combination, signalling means on a locomotive, said means comprising a master relay having an armature movable between contacts at variable rates in accordance with the frequency of coded impulses corresponding to traific conditions in advance of said locomotive; signalling means on a trailing loco-motive, comprising a master relay having an armature movable between contacts at variable rates; and connections whereby the armature of the second master relay is caused to move at the same rate as that of the first master relay.

2. In combination, signalling means on a locomotive, said means comprising a master relay having an armature movable between contacts at variable rates in accordance with the frequency of coded impulses corresponding to trafiic conditions in advance of said locomotive; signalling means on a trailing locomotive, comprising a master relay having an armature movable between contacts at variable rates; and connections controlled by the first master relay whereby the armature of the second master relay is caused to move at the same rate as that of the first master relay.

3. In'combination, locomotive cab signaling means comprising a master relay having an armature operable at different speeds for causing current pulsations of different frequencies, a second locomotive. cab signalling means comprising. a master relay having an armature operable at different rates for causing current pulsations of different frequencies, and connections for causing operation of the armature of the second master relay at the same rate tl e first master relay.

4. In combination, locomotive cab signallin means comnrisin a source of ener h I m n.

and a master relay having an armature operable at different speeds for controlling said source to cause energy pulsations of different frequencies, a second locomotive cab signaling means comprising a master relay having an armature operable at different rates for causing current pulsations of different frequencies, and connections from suit. source and controlled by the first master relay for causing the armature of the second master relay to operate at the same rate the arma ture of the first master relay.

5. In combination, locomotive cab signalling means comprising a master relay having an armature engageable with a pair of contacts alternately, and a decoding transformer having its primary winding connected to said contacts; 'ab signalling means on a second locomotive, comprising a master relay; and means comprising connections from the second master relay to said contacts whereby the first master relay causes energization of the second master relay concurrently with the supply of energy to said docoding transformer.

6. In combination, locomotive cab signalling meai'iscon'iprising a master rel y having an armature engageable with a pair of contacts alternately, a source of energy connected to said armature, and a decoding transformer having its primary winding connected to said contacts; cab signalling means on a second locomotive, comprising a mast-er relay having an armature engageable with a pair of contacts alternately; and means comprising connections from the first mentioned pair of contacts to the second master relay for causing the armature thereof to. operate at the same rate as the armature of the first master relay and as an incident to the supply of energy to said decoding transformer.

7, In combination, locomotive cab signalling means comprising a master relay, a second locomotive cab signalling means comprising a master relay, and connections controlled by the armature of the first mentioned relay for causing in the second relay current pulsations producing movement of the armature of the second relay at the same rate as that of the first relay.

8. In combinatlon,locomotive cab signalling means comprising a master relay having an armature operable at different speeds, a

secondlocomotive cab signalling means comprising a master transformer and a master relay having a winding connected to the secondary of said transformer, and connections controlled by the first relay for producing in the windingsof the second relay current pulsations causing movement of the armature of said second relay at the same rate as that of the first relay.

9. In combination, locomotive cab signalling means. comprising a. master relay, a second relay, and connections controlled by the armature of the first mentioned relay for causing in the second relay current pulsations producing movement of the armature of the second. relay at the same rate as that of the first relay.

10. In combination, two sets of locomotive cab signalling apparatus each comprising a master transformer, a master relay connected with the secondary of such master transformer and a decoding transformer having a primary circuit controlled by the master relay; and means for connecting the primary of one of said decoding trai'isformers with the secondary of the master transformer of the other set of apparatus.

11. In combination, two sets of locomotive cab signalling apparatus each comprising a master transformer, a master relay connected with the secondary of such master transformer and a decoding transformer having a primary circuit controlled by the master relay; and means for connecting the secondary of one decoding transformer with the master relay of the other set of apparatus.

12. In combination, two sets of locomotive cab signalling apparatuseach comprising a master transformer, a master relay connected with the secondary of such master transformer and a decoding transformer having a primary circuit controlled by the master relay; and means for connecting the primary of one of said decodin transformers inv series with the master relay and master transformer secondary of the other set of apparatus.

In testimony whereof, we have signed our names to this specification this th day of September, 1930.

F tANK II. NICHOLSON. 

